On 2023-09-03 13:11, Alejandro Colomar wrote: > Hi Paul, > > On 2023-09-03 04:09, Paul Smith wrote: >> On Sun, 2023-09-03 at 01:03 +0200, Alejandro Colomar wrote: >>> I was also wondering... is ONESHELL significant for performance? >>> Does the reduction in number of shells speed up things? >> >> It might increase performance but that's not what it's for primarily, > > For those wondering, here's an experiment with a rule that runs a few > shells (given appropriate values for certain variables): > > > $ time make -j install DESTDIR=/tmp/foo Z=.gz LINK_PAGES=symlink >/dev/null > > real 0m6.229s > user 0m17.820s > sys 0m5.269s > $ sed -i '/ONESHELL/s/^/#/' GNUmakefile > $ time make -j install DESTDIR=/tmp/bar Z=.gz LINK_PAGES=symlink >/dev/null > > real 0m8.511s > user 0m23.823s > sys 0m7.511s > > > It's not orders of magnitude, but it might be interesting to cut a > 25%, considering no obvious pitfalls (when you overcome the SHELL > errors, that is :D). For rules with just 1 canned recipe, the times > didn't change. > > Here's the rule I used (I chose it because it's the most complex rule > in the Makefile, as it has 3 canned recipes): > > > $(_manpages): > $(info INSTALL $@) > <$< \ > $(SED) $(foreach s, $(MANSECTIONS), \ > -e '/^\.so /s, man$(s)/\(.*\)\.$(s)$$, $(notdir > $(man$(s)dir))/\1$(man$(s)ext)$(Z),') \ > | $(INSTALL_DATA) -T /dev/stdin $@ > ifeq ($(LINK_PAGES),symlink) > if $(GREP) '^\.so ' <$@ >/dev/null; then \ > $(GREP) '^\.so ' <$@ \ > | $(SED) 's,^\.so \(.*\),../\1,' \ > | $(XARGS) -I tgt $(LN) -fsT tgt $@; \ > fi > endif > ifeq ($(Z),.bz2) > if ! $(TEST) -L $@; then \ > $(BZIP2) $(BZIP2FLAGS) <$@ \ > | $(SPONGE) $@; \ > fi > else ifeq ($(Z),.gz) > if ! $(TEST) -L $@; then \ > $(GZIP) $(GZIPFLAGS) <$@ \ > | $(SPONGE) $@; \ > fi > else ifeq ($(Z),.lz) > if ! $(TEST) -L $@; then \ > $(LZIP) $(LZIPFLAGS) <$@ \ > | $(SPONGE) $@; \ > fi > else ifeq ($(Z),.xz) > if ! $(TEST) -L $@; then \ > $(XZ) $(XZFLAGS) <$@ \ > | $(SPONGE) $@; \ > fi > endif > > > >> at least not in my opinion. It's there for people who want to use >> shells other than POSIX sh as their SHELL value, > > Well, my SHELL is not the POSIX sh, as I'm using bash(1), but I get > it's still POSIX-sh-like, not python. :) > >> where it's not so easy >> to create an entire script on a single line and using backslashes. > > Can we really call it script if it's invoked via sh -c? It's more > like a command line. :) > > Jokes apart, can you put an example of such a scenario? I'm not > imagining it.
Never mind; a python script could be it. > > > BTW, apart from fixing the SHELL (which was a good thing, anyway), > the only change I needed was to remove the '+' from a couple of > recipes (and keep only the first one). Not a big deal. Most rules > work without modification. > > > Cheers, > > Alex > -- <http://www.alejandro-colomar.es/> GPG key fingerprint: A9348594CE31283A826FBDD8D57633D441E25BB5
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